Justification:Austropotamobius torrentium has been assessed as Data Deficient. While this species is relatively widespread across Europe it is undergoing significant declines throughout much of its range. However, rates of decline have not been quantified and therefore this species cannot be assessed under criterion A. Further research on rates of decline is urgently needed before an accurate assessment of conservation status can be made.

Albania: There is no information on the population status of this species in this country.

Austria: The Signal Crayfish is driving rapid declines in the population numbers of this species (Holdich et al. 2009). This species is most abundant in Austria and Germany. In Austria, there are 534 localities which are said to account for 46% of all crayfish populations (Pöckl 1999).

Bosnia-Herzogovina: There have been mass mortalities of this species (Holdich et al. 2009).

Bulgaria: There are only a few small subpopulations of this species (Zaikov and Hubenova 2007). Nothing is known on the status of this species in this country.

Croatia: This species is thought to be reasonably well preserved in this country, however anthropogenic pressure on this species habitat is increasing and likely to be driving some declines in abundance. Some parts of the population have also been significantly impacted by drought which has caused 95% mortality in some streams (I. Maguire pers. comm. 2010).Austropotamobius torrentium is a native species and occurs in springs and streams at higher elevations. Even a co-existance of this species with Astacus astacus and with Austropotamobius pallipes is recorded (Meguire 2009).

Czech Republic: It is unclear whether this species is native or introduced to this country. It has been found at varying densities in streams, but in a study by Kozak et al. (2002) they found it at a density of 12 individuals/ km2 in Klabava Brook.

France: This species is considered to be close to extinction within this country (Collas, Julien and Monnier 2007)

Germany: This species is undergoing a decline however there no trend information is available (H. Schulz pers. comm. 2009).

Greece: This species can be found in 11 out of the 50 prefectures (Koutrakis et al. 2007). Compared to the other 2 crayfish species found in Greece, this species is believed to have undergone the greatest decline. However there is indication of recovery in some areas (Koutrakis et al. 2007).

Hungary: This species is threatened by organic pollution and the spread of non-native crayfish species which has resulted in a decline in the population numbers (P. Miklós pers. comm. 2009).

Italy: The species is fragmented in its distribution. In the Province of Udine, 2 of the 3 populations recorded in 1995 have gone extinct in 2005 (Machino and Füreder 2005). There has been a strong decline in this species in Northern Italy (Füreder 2009).Macedonia: There is no information on the population status of this species in this country.Montenegro: Austropotamobius torrentium is already thought to have gone extinct in a tributary of Lake Ohrid (Koselska Brook) below Rečica as a result of pollution (Y. Machino pers. comm. 2009).Romania: There is no information on the population status of this species in this country.Serbia: There is no information on the population status of this species in this country.Slovakia: This species is rare in this country, but population numbers are thought to be stable at present (P. Manko pers. comm. 2009).

Slovenia: There is no information on the population status of this species in this country.Switzerland: This species is known from the eastern parts of Switzerland where it is known to be in severe decline. It is considered to be 'highly endangered' by the Swiss National Legislation on Fisheries (D. Hefti pers. comm. 2009).

Turkey: There is no information on the population status of this species in this country.

This species is most commonly found in headwater streams with plenty of riparian and instream cover, however it has occasionally been found in lowland rivers (Souty-Grosset et al. 2006). Female size at maturity has been observed at 4.61 cm (total length) (I. Maguire pers. comm. 2010. Recorded sizes for A. torrentium ranged from 6 to 9 cm (females) and from 8 to 10.5 cm (males) (Laurent 1988).

The ovigerous females carried external eggs from early November until mid-June the following year (Maguire et al. 2002). In Germany, stone crayfish females may incubate 40 to 70 eggs (Laurent 1988). The maximal number of eggs per female (in Croatia) we found was 104 (an average value was 53.56) (Maguire et al. 2002).

In populations studied in Austria, a maximum of 86 eggs per female was found, while in Croatian populations the number of eggs per female was maximally 117 (Maguire et al. 2009).

Declines in this keystone species are said to negatively impact both ecosystem structure and function within freshwater environments through loss of: a) provisioning services – food production from fisheries, recreational fishing, b) regulatory and support services – trophic cascades, water purification, nutrient cycling, primary productivity, c) cultural value – recreational fishing, education, heritage. Crayfish are also an important food source to a range of species including otters, salmonids, and birds such as kingfishers (Kettunen and ten Brink 2006).

This species is most threatened by the presence of non-native species such as the Signal Crayfish (Pacifastacus leniusculus) and the Spiny-cheek Crayfish (Orconectes limosus), crayfish plague (Aphanomyces astaci), and habitat loss and degradation (Füreder et al. 2006). This species is not tolerant of environmental change, so threats such as domestic and industrial pollution, agriculture, sedimentation, eutrophication, damming, water abstraction, and channelisation have all negatively impacted this species (Füreder et al. 2006). This species is reported to be undergoing significant population declines in most of the countries in which it is known from, however no quantitative data on the rate of decline is available.

This species is listed under the Annex II of the EU Habitats Directive as a species requiring special conservation measures (Souty-Grosset et al. 2006). It is also listed on the German Red List (RL3, Appendix 1), and within a number of other countries as threatened (Souty-Grosset et al. 2006). This species is also listed under Appendix III of the Bern Convention.

Rates of population decline are needed through long-term population monitoring.

In-Place Research, Monitoring and PlanningIn-Place Land/Water Protection and ManagementIn-Place Species ManagementIn-Place Education Included in international legislation:Yes Subject to any international management/trade controls:Yes